1. Field of the Invention
The present invention relates to an image capture apparatus and, more particularly, to an image capture apparatus having a function of detecting its orientation inclination.
2. Description of the Related Art
In recent years, an image capture apparatus such as a digital camera can detect its inclination angle by detecting the direction of gravity using, for example, an acceleration sensor. Thus, a photograph with no inclination can be captured by notifying the photographer of the inclination of the image capture apparatus. The orientation of an image capture apparatus in the direction of gravity can also be detected by mounting a gravity sensor such as an acceleration sensor in it, so the number of image capture apparatuses which implement a electronic level function is increasing.
Japanese Patent Laid-Open No. 2009-261030, for example, discloses a technique of displaying the inclination status of an image capture apparatus with respect to the horizontal level on its display screen using its inclination information with respect to the direction of gravity. Also, Japanese Patent Laid-Open No. 2009-92526 discloses a technique of adjusting the zero point by rotating the main body of an electronic level which uses an acceleration sensor through 180°.
However, the output value of a sensor such as an acceleration sensor for use in inclination detection changes in response to a change in environment such as temperature, thus posing a problem that the zero point position indicating the horizontal level may shift depending on the use environment.
As one method of solving this problem, zero point position correction by the user is known. An image capture apparatus is fixed horizontally, and the zero point position of a electronic level is corrected using the output value of an acceleration sensor at that time. However, this method results in erroneous zero point position correction without detecting a correct zero point if the output value of a sensor which detects the inclination varies due to the influence of vibration or an acceleration other than a gravitational acceleration during zero point position correction.